Digital cameras, movie recorders and personal computers with camcorder attachment create, store and display digital images. These devices often need to generate thumbnails. Thumbnails are objects that are a portion of the image. Generation of thumbnails shows the user all image components in a single screen for searching or previewing the images. The prior art reduces the resolution of the original image to a level suited to the thumbnail size. Many image-resizing technologies exist to generate a lower resolution image. The main disadvantage of this prior art image resizing is that the resolution of the device screen is the deciding factor in giving the best image clarity. Showing a reduced resolution image will always be worse than showing a high resolution window of the original image.
When compared to an original high-resolution image, a resized image using commercially available image management tools is recognizable only from its overall appearance and shades, but specifics are lost. Digital still cameras create, store and process digital pictures. The size of the target monitor or viewing device is one of the important parameters for getting satisfactory displays when a digital picture is viewed. For example, a picture taken with the highest resolution in a 5 Mega Pixel camera, which includes many objects, may not display well in a 1.5 inch LCD display, if displayed in full size. When viewing and searching a large collection of images, it is difficult to quickly find a required image if there are too many objects in each image. Hence there is a need to create smaller sized equivalents (called thumbnails) of a high resolution picture, for storage and quick search. These thumbnails may also be used to reduce the search target area for content retrieval algorithms like MPEG-7. Several prior art methods generates thumbnails. Most of these methods rely on color information and face-detection.